1. Field of the Invention
This invention relates to treating body tissue, particularly to treating body tissue by altering the shape, density, relative geometry or tension of that body tissue using energy or substances deployed from an interstitial location in the body.
2. Related Art
Urinary incontinence results from a number of factors. Increasing age, injury from childbirth and related stresses can cause the relative tone of the bladder and accessory muscles to weaken, which, in turn, causes an impaired inability to retain urine. Weight gain and overall deterioration of muscle tone can cause increased abdominal pressure which overcomes sphincter resistance. Nerve pathways that cause the “urge” to urinate can be hyperactive. The relative tension of the urethra can change with age, causing poor urinary control. Injury to the detrusor muscles or to the trigone area also results in impaired urinary continence.
These factors do not usually occur by themselves. The typical patient usually presents with two or more of them. Therefore, it is desirable to provide a treatment that can address many of these factors.
Given the complex etiology of varied causal factors, the ideal treatment for urinary incontinence requires a device that can perform many different functions. For example, a treatment for female urinary incontinence might rely upon some or all of the following:
(1) reshaping the bladder to alter the urethro-vesical angle and re-suspend the bladder neck, (2) manipulation of the detrusor muscles, (3) mapping and modulating nervous pathways responsible for urinary urgency, (4) reducing strain on he bladder neck by changing the structural geometry, (5) shrinking discrete and non-discrete areas of the bladder by creating thermal lesions, (6) three-dimensional modeling of tissue by adding bulk so as to achieve better closure, (7) strengthening the structure integrity of a tissue by providing a pattern of scar tissue, and (8) application of pharmaceutical agents both as a curative and to promote healing post treatment.
The use of a catheter to apply radio frequency (RF) and other types of energy to ablate tissue in the body (such as heart muscle tissue) is known in the art of cardiac treatment. However, known systems using RF and other types of energy are still subject to several drawbacks.
A first problem in the known art involves providing a device that can perform all of the aforementioned functions. While known systems can perform one or more of these functions, nothing in the related art is capable of performing all of these functions. Patients are frequently required to return for multiple treatments until a cure is finally effected.
A second problem in the known art involves identification, modulation and/or stimulation of nerves in a targeted tissue. Known systems do not provide for protection of sensitive nerves during treatment or allow nerves during treatment or allow nerves to be identified and stimulated. This is particularly problematic because many tissue disorders, especially those involving tone or contractile ability of a sphincter, arise from afferent and efferent nerves are either under-stimulated or over-stimulated.
A third problem in the known art involves providing a treatment surface that can reach all of the desired treatment areas, such as the entire surface of the detrusor muscles. While the use of a catheter to deploy energy is known, none is disposed to flexibility adapt to the interior shape of an organ so as to provide optimal uniform treatment.
A fourth problem is the known art involves removal of tissue and substances used in treatment. Known systems do not provide for removal of excess substances used in treatment such as cooling fluids, collagen or bulking substances. Similarly, known systems do not provide for removal of substances that hinder or otherwise obstructs the healing process such as pus, purulent discharges, suppuration and pockets of infection.
A fifth problem in the known art involves directing and positioning the electrodes in the body cavity orifice. Difficulties in accurately positioning the electrodes in the target orifice detract from treatment. Frequently; unhealthy tissue remains untreated while healthy tissue is compromised. Difficulties in directing and positioning the electrodes are particularly problematic because one of the goals of treatment is to minimize collateral damage to healthy tissue and to completely treat diseased tissue.
A sixth problem in the known art involves minimizing thermal injury to the patient. Some known systems rely upon simultaneous application of energy and infusion of a cooling liquid into the targeted area for treatment. While such infusion of liquid minimizes thermal injury to the patient, it is not applicable to all parts of the body. For example, infusion of cooling liquids into an internal body cavity such as a bladder, uterus, or stomach can rupture the targeted organ or cause osmotic imbalance within the tissue.
A seventh problem in the known art involves difficulty in the simultaneous use of complimentary technology. Known systems do not provide for optimal, simultaneous use of auxiliary tools for visualization, monitoring pH and pressure or drug administration.
An eighth problem in the known art is that it can be difficult to block the flow of body fluids and gases into an area of the body where tissue ablation is taking place. Bodily fluids can dissipate and detrimentally absorb the energy to be applied to the tissue to be ablated. Dissipation of bodily fluids detracts from the goal of treatment of diseased tissue.
Accordingly, it would be advantageous to provide a method and apparatus for treatment or body structures, especially internal body structures involving unwanted features or other disorders, that does not require relatively invasive surgery, and is not subject to other drawbacks noted with regard to the known art. This advantage is achieved in an embodiment of the invention in which a relatively minimally invasive catheter is inserted into a body, a variety of different treatments of the body structures is applied using electrodes and a cooling element, and the unwanted features or disorders are relatively cured.